Generally, a papermaking process includes several steps. Typically, an aqueous slurry of papermaking fibers is formed into an embryonic web on a foraminous member, such, for example, as a Fourdrinier wire. After the initial forming of the paper web on the Fourdrinier wire, or forming wires, the paper web is carried through a drying process or processes on another piece of papermaking clothing in the form of endless belt which is often different from the Fourdrinier wire or forming wires. This other clothing is commonly referred to as a drying fabric or belt. While the web is on the drying belt, the drying or dewatering process can involve vacuum dewatering, drying by blowing heated air through the web, a mechanical processing, or a combination thereof. in through-air-drying processes developed and commercialized by the present assignee, the drying fabric may comprise a so-called deflection member having a macroscopically monoplanar, continuous, and preferably patterned and non-random network surface which defines a plurality of discrete, isolated from one another deflection conduits. Altematively, the deflection member may comprise a plurality of discrete protuberances isolated from one another by a substantially continuous deflection conduit, or be semi-continuous. The embryonic web is associated with the deflection member. During the papermaking process, the papermaking fibers in the web are deflected into the deflection conduits and water is removed from the web through the deflection conduits. The web then is dried and can be foreshortened, by, for example, creping. Deflection of the fibers into the deflection conduits of the papermaking belt can be induced by, for example, the application of differential fluid pressure to the embryonic paper web. One preferred method of applying differential pressure is exposing the web to a fluid pressure differential through the drying fabric comprising the deflection member.
Through-air-dried paper webs may be made according to any commonly assigned and incorporated herein by reference U.S. Pat. No. 4,529,480 issued to Trokhan on Jul. 16, 1985; U.S. Pat. No. 4,637,859 issued to Trokhan on Jan. 20, 1987; U.S. Pat. No. 5,364,504, issued to Smurkoski et al. on Nov. 15, 1994; U.S. Pat. No. 5,529,664, issued to Trokhan et al. on Jun. 25, 1996; and U.S. Pat. No. 5,679,222, issued to Rasch et al. on Oct. 21, 1997.
Generally, a method of making the deflection member comprises applying a coating of liquid photosensitive resin to a surface of a foraminous element, controlling the thickness of the coating to a pre-selected value, exposing the coating of the liquid photosensitive resin to light in an activating wave-length through a mask, thereby preventing or reducing curing of selected portions of the photosensitive resin. Then the uncured portions of the photosensitive resin are typically washed away by showers. Several commonly assigned U.S. Patents which are incorporated herein by reference, disclose papermaking belts and methods of making the belts: U.S. Pat. No. 4,514,345, issued Apr. 30, 1985 to Johnson et al.; U.S. Pat. No. 4,528,239, issued Jul. 9, 1985 to Trokhan; U.S. Pat. No. 5,098,522, issued Mar. 24, 1992; U.S. Pat. No. 5,260,171, issued Nov. 9, 1993 to Smurkoski et al.; U.S. Pat. No. 5,275,700, issued Jan. 4, 1994 to Trokhan; U.S. Pat. No. 5,328,565, issued Jul. 12, 1994 to Rasch et al.; U.S. Pat. No. 5,334,289, issued Aug. 2, 1994 to Trokhan et al.; U.S. Pat. No. 5,431,786, issued Jul. 11, 1995 to Rasch et al.; U.S. Pat. No. 5,496,624, issued Mar. 5, 1996 to Stelijes, Jr. et al.; U.S. Pat. No. 5,500,277, issued Mar. 19, 1996 to Trokhan et al.; U.S. Pat. No. 5,514,523, issued May 7, 1996 to Trokhan et al.; U.S. Pat. No. 5,554,467, issued Sep. 10, 1996, to Trokhan et al.; U.S. Pat. No. 5,566,724, issued Oct. 25, 1996 to Trokhan et al.; U.S. Pat. No. 5,624,790, issued Apr. 29, 1997 to Trokhan et al.; U.S. Pat. No. 5,628,876 issued May 13, 1997 to Ayers et al.; U.S. Pat. No. 5,679,222 issued Oct. 21, 1997 to Rasch et al.; and U.S. Pat. No. 5,714,041 issued Feb. 3, 1998 to Ayers et al., the disclosures of which are incorporated herein by reference.
While curing of the photosensitive resin has proved to be an effective way of making the papermaking belt, a search for improved methods and products has continued. Now, it is believed that the deflection member may be made by at least several other methods which do not necessarily require the use of the curing radiation.
Accordingly, the present invention provides a novel process for making a papermaking belt by first, forming a desired pattern of a fluid resinous material in a molding member, and then transferring the resinous material from the molding member to the reinforcing structure and solidifying the patterned resinous material. The present invention also provides a process wherein the transferal of the resinous material from the molding member to the reinforcing structure is assisted by application of fluid pressure differential. The present invention also provides a process that reduces the amount of the resinous material required to construct the papermaking belt comprising a reinforcing structure and a patterned resinous framework. The present invention also provides an apparatus comprising a molding member for forming a desirable pattern of the resinous material and subsequently transferring the patterned resinous material to the reinforcing structure of the belt being constructed.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description, in conjunction with the accompanying drawings.